: This proposal presents Phase II of Mercury Biomed's plan for commercializing the new and innovative WarmSmart technology to more effectively keep surgical patients normothermic. WarmSmart embodies several breakthrough concepts in bioheat transfer to manage core temperature. We are building a cost- competitive patient warming technology that will be superior to existing technologies while being more convenient, easy to use, and safe. Well-established clinical evidence shows that unwarmed anesthetized patients rapidly become about 2C hypothermic. We have also shown in many randomized trials that this degree of hypothermia promotes surgical site infection, impairs drug metabolism, and increases blood loss and transfusion requirement. The most widely applied technology for keeping patients warm during surgery uses heating applied over large areas of the body surface via forced convection of hot air through a cover surrounding patients. A recent study of surgical patients shows that this technology fails to keep patients above the minimum acceptable core temperature (36C) in two-thirds of patients. Forced-air covers also occupy large fractions of the body surface which can restrict access to patients during surgery. WarmSmart requires access to only the hands and feet where uniquely high rates of blood flow can occur through glabrous skin. The Division of Pharmacology, Physiology and Biological Chemistry has a list of approved topics that include ??development of ?treatments involved in?peri-operative?conditions? and this project advances those objectives. In Phase I, we made considerable advances in both the technology and understanding of the human physiology related to the technology. Both Phase I specific aims were accomplished through: 1) executing physiological experiments in humans that provided conclusive evidence that our system reduces the vaso- constriction threshold (core temperature triggering thermoregulator vasocontriction) in patients subjected to a cooling stimulus; and, 2) building a fully functioning working prototype of a solid-state system that uses Positive Temperature Coefficient heating apparatus at the glabrous skin region to efficiently transfer heat to the human body. Phase II of the project will have five specific aims to prepare for the commercialization of the WarmSmart device: 1) measure the physiological sensitivity of the Selective Thermal Stimulation (Temperature, Cycle times, STS Location); 2) determine the rate at which the WarmSmart system can warm anesthetized patients; 3) test the hypothesis that the WarmSmart system's performance is non-inferior to current forced-air warming solutions; 4) design and develop a commercializable WarmSmart system; and, 5) secure FDA approval for the WarmSmart system.